The present invention, in some embodiments thereof, relates to composite material bone implant devices and to manufacturing methods for such devices. More particularly, but not exclusively, the invention in some embodiments relates to such devices and methods as applied to implant devices formed of fiber-reinforced polymer matrices. Still more particularly, the invention in some embodiments relates to the surface characteristics of such implant devices, such as may be conferred, for example, by a surface coating.
Carbon fiber composite bone plates provide advantages in some properties over bone plates made of metal. A rigid metal bone plate creates relatively high stresses in certain regions of the bone, with insufficient load transfer, resulting in stress shielding. Both high stress and stress shielding can cause bone deterioration and resorption, leading to areas of bone weakness and loss of bone support for the implant.
Non-metal implants made of a lighter and more flexible material, yet having sufficient strength for load bearing, have been suggested in the past. In particular, composite material implants, for example formed of polymer reinforced with fibers, are discussed in U.S. Pat. No. 4,750,905; U.S. Pat. No. 5,181,930; U.S. Pat. No. 5,397,358, U.S. Pat. No. 5,009,664, U.S. Pat. No. 5,064,439, U.S. Pat. No. 4,978,360, and U.S. Pat. No. 7,419,714 the disclosures of which are incorporated herein by reference. Bone implants with coatings with properties affecting, for example, osteo-integration, bone regrowth, and biomimetic properties are discussed in European Patent Application EP19850304670, published as EP0169001; International Patent Application No. PCT/IB2004/003260, published as WO2006038056, International Patent Application No. PCT/CH2000/000382, published as WO2002004038; and European Patent Application EP20090702015, published as EP2245209.
The present invention addresses improvements in the above-noted areas, and in other areas of composite bone implant technology.